Bitcoin is kicking off the last month of 2018 with another downward drop.

After ending November deeply in the red, the world's largest cryptocurrency fell as much as 8 percent on Monday to a low of $3,790.96, according to data from CoinDesk.

At this time last year, bitcoin was beginning its climb to almost $20,000 and ended last December up 40 percent. It entered its hot streak just after Thanksgiving last year, surging in price largely because retail investors were buying in.

But the tail end of this year has been a different story: Bitcoin is now down 73 percent since the beginning of January. Twenty-four-hour trading volumes are down 56 percent since Jan. 1, while the entire cryptocurrency market capitalization has fallen 80 percent.

Other cryptocurrencies also fell on Monday. XRP, the world's second-largest by market value, was down 5 percent, according to CoinMarketCap. Ether fell 8 percent.

Crackdowns by U.S. regulators and a breakdown in key technical levels were main reasons analysts cited for the slow price decline in November. Michael Moro, CEO of Genesis Global Trading, said "it didn't take much for the price to break down" after bitcoin failed to stay above the key support level of $5,850.

Despite the price drops, some in the industry are still bullish.

Mati Greenspan, senior market analyst for trading platform eToro, pointed to a study from Glassdoor.com showing bitcoin and blockchain jobs rose 300 percent in one year, and "have never been in higher demand."

"In any case, the crypto industry is shining brightly at the moment," Greenspan said.